Leaf hydraulic conductivity and photosynthesis are genetically correlated in an annual grass
Hafiz Maherali1, Mark E Sherrard1, Megan H Clifford1
1Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G2W1, Canada.
Abstract:
Comparative studies suggest that a positive correlation between xylem water transport and photosynthesis is adaptive. A requirement for the adaptive evolution of coordination between xylem and photosynthetic functions is the presence of genetic variation and covariation for these traits within populations. Here it was determined whether there was genetic variation and covariation for leaf blade hydraulic conductivity (K(W)), photosynthetic rate (A), stomatal conductance (g(s)), and time to flowering in a population of recombinant inbred lines of Avena barbata, a Mediterranean annual grass. Significant (P < 0.05) broad-sense heritabilities (H(2)) were detected for K(W) (H(2) = 0.33), A (H(2) = 0.23) and flowering time (H(2) = 0.62), but not for g(s). Significant positive genetic covariation between A and K(W) was also observed. There was no other genetic covariation among traits. The first evidence of genetic variation for K(W) within a species was obtained. These results also indicate that there is a genetic basis for the positive association between xylem water transport and photosynthesis. The presence of significant genetic variation and covariation for these traits in natural populations would facilitate correlated evolution between xylem and leaf functions.
Related Concept Videos
Light Acquisition
Adaptations that Reduce Water Loss
Responses to Drought and Flooding
Biological Clocks and Seasonal Responses
Regulation of Transpiration by Stomata
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...


